1. Field of the Invention
The present invention relates to an electronic musical instrument, and more particularly to an electronic musical instrument which can store key operation data corresponding to a musical performance played by using a keyboard and which can also transfer the stored key operation data to an external memory.
2. Prior Art
Conventionally, a recent electronic technology develops an electronic musical instrument which can store performance data corresponding to a keyboard performance in an internal memory so that an automatic performance will be played by use of the stored performance data. Such electronic musical instrument can transfer the performance data stored in the internal memory to an external memory as disclosed in an automatic performance apparatus of Japanese Patent Laid-Open No. 59-139093.
If a storage capacity of the external memory is set smaller than a quantity of the performance data stored in the internal memory (hereinafter, simply referred to as "an internal data quantity") in the conventional electronic musical instrument capable of executing a data transfer to the external memory, the stored performance data are inhibited from being transferred to the external memory, i.e., the data transfer is not executed at all. In this case, the conventional electronic musical instrument wastes the whole musical performance which is played in order to transfer the performance data to the external memory.
In the above-mentioned case, by lighting up a light emitting diode (LED) or by displaying a predetermined message on a liquid crystal display device or the like, a player can be informed that the data transfer is inhibited from being executed.
By using the above-mentioned LED or the liquid crystal display device, the player can know that the data transfer is inhibited from being executed, but the player can not know how much is the storage capacity of the external memory short of a desirable storage capacity. Therefore, it is impossible for the player to know how much the performance quantity (or the data quantity) can be transferred to the external memory. In other words, the conventional electronic musical instrument cannot give the player the information about how much of the performance quantity can be transferred to the external memory.